CD-ROM Drive

ABSTRACT

Abstract of Disclosure 
     Given a CD-ROM drive having a plurality of speed ranges selectable in n-fold graduation and having linearly reduced rotational speeds within each speed range respectively between outer and inner sector and having the prescription that a reduction of the rotational speed automatically ensues given a negative read result, control means are provided that effective switching into a lower speed range when a predetermined noise level is upwardly transgressed and/or when vibrations occur.

Background of Invention

[0001] The invention is directed to a CD-ROM drive.

[0002] A prior art CD-ROM drive is disclosed in the publication, PioneerElectronic Corporation XP0020066715, 17 September 1996.

[0003] In conformity with the demands made of higher read performances,CD-ROM drives work with higher and higher speeds. Proceeding fromsingle, double, through currently 8-fold speed, corresponding driveswith speeds in the range from 500 through 6,500 rpm are offered, so thatthe drives can be set to different speed ranges as needed. By contrastto hard disk drives wherein an extremely precise adjustment andcentering is possible due to the permanently installed hard disks, thereis the problem given CD-ROM drives that an adequately exact centeringcan be achieved here for only a relatively small part of the data disksthat can be inserted into the drive. Particularly given increasingspeeds, this results therein that vibrations and/or running noises thatconsiderably complicate and impede the work execution at acorrespondingly equipped personal computer occur due to the non-optimumposition given a majority of the data disks that are inserted. Inaddition to a high noise emission due to the drive, which can alsoextend onto the entire housing, this leads to unnecessarily highmechanical stresses of the drives, which in turn results in maintenance,repair and other consequential costs. Vibrations that occur at theCD-ROM drive can usually also be transmitted onto neighboring hard diskor floppy disk drives, so that their operation can be sensitivelydisturbed. Ultimately, this leads to dissatisfaction on the part of thecustomer, who no longer accepts CD-ROM drives overall.

[0004] As known, the tracks in a compact disk are applied in the form ofa helix proceeding from inside to outside, whereby all sectors are ofequal length, differing from a hard disk. Dependent on the operatingmode of the CD-ROM drive, this means either that the speed of thecompact disk is linearly reduced from, for example, 6,500 rpm to 3,000rpm from the first sector arranged at the inside to the last sectorarranged at the outside within a predetermined speed range (what isreferred to as CLV mode) of that the speed remains constant, with theresult that the read speed steadily increases toward the outside (whatis referred to as CAV mode). When it then occurs that a sector cannot befaultlessly read, then the drive automatically switches into thenext-lower speed range.

[0005] An analogous operation is not provided per se when vibrationsand/or noise emissions occur. However, it has been disclosed for whatare referred to as dual mode CAV/CLV drives (see the above-identifiedproduct specification of the Pioneer company, September 19966) hat anautomatic switch from CLV mode into the CAV modes ensues when vibrationsoccur, i.e. a switch to a speed that is constant within the selectedspeed range but that is somewhat lower overall, with the advantage thatthe risk of occurring resonances within the selected speed range issignificantly lower given a fixed speed.

Summary of Invention

[0006] The present invention is based on the object of improving aCD-ROM drive in such a way that an operating sequence deteriorated dueto vibrations and/or noise emissions can be avoided with simple meansand the CD-ROM drive in turn returns into a malfunction-free operation.

[0007] In general the present invention is a CD-ROM drive having aplurality of speed ranges selectable in n-fold graduation and,optionally, having constant or linearly reduced rotational speeds withineach speed range respectively between outer and inner circumference,with the prescription that a switching to a lower speed automaticallyensues using control means when vibrations occur. A manually actuatablekey for switching the drive into a speed range respectively lower by onestep (n-1) is allocated to the control means for speed reduction.

[0008] Advantageous developments of the present invention are asfollows.

[0009] The key for switching into a lower speed range is combined withthe control key for the CD drawer transport and respectively one of thetwo functions can be triggered dependent on the duration of the keypressure.

[0010] The control key for the drawer transport is controllable suchthat, given brief-duration activation of the key, a speed reduction istriggered and, given longer key pressure, a transport motion of the CDdrawer is triggered.

[0011] Advantageous developments of the invention are recited below. Itis especially advantageous when the control key for switching the driveinto a lower speed range is combined with the control key for the CDdrawer transport because there is usually hardly any space for a furtheroperating key given traditional drives. Dependent on the duration of thekey pressure, either the function of speed reduction or the function ofdrawer transport is triggered.

Brief Description of Drawings

[0012] The features of the present invention which are believed to benovel, are set forth with particularity in the appended claims. Theinvention, together with further objects and advantages, may best beunderstood by reference to the following description taken inconjunction with the accompanying drawings, in the several Figures ofwhich like reference numerals identify like elements, and in which:

[0013]FIG. 1 depicts the schematic circuit diagram of a CD-ROM drive;and

[0014]FIG. 2 is a flow chart for the inventive operation of the CD-ROMdrive.

Detailed Description

[0015]FIG. 1 shows the fundamental structure of a CD-ROM drive. It iscomposed of a spindle 2 driven with the assistance of a motor 1 and ontowhich a CD disk 3 is centrally placed. The signals picked up by thescanner optics 4 are supplied to a data processor 5 for furtherprocessing. Another processor 6 monitors, first, the respectivelycurrent position of a switch S and supplies control signals for themotor control 7 and the drawer control 8 that controls the transport ofthe CD disk 3 into the operating position, i.e. to the spindle 2, andfrom this point back into the removable station. Dependent on theon-time of the switch S, the processor 6 either supplies a signal to themotor control 7 for reducing the speed or a signal to the drawer control8 for the transport of the CD disk from the operating position into theoutput position.

[0016] The operation of the CD-ROM drive shall be explained in yetgreater detail on the basis of flow charts that are shown in FIG. 2. Inthe routine "monitor", the function of the switch S, i.e. its switchstatus -on/off -, is monitored in predetermined interrogation cycles.When the switch S is actuated, the change in switch status is variablymonitored and checked for rebounding an active condition, for examplefor approximately 100 ns. When the switch is no longer active after apredetermined time span of, for example, less than 0.5 seconds, a branchis made into the routine "SB". Otherwise, i.e. when the switch remainsactive for a longer time, a check is carried out to see whether thisactive condition has lasted for at least two seconds. When this is true,a branch is made into the routine "E", which means that the CD disk isejected, i.e. the drawer with the CD disk is opened. Upon insertion of anew data disk, the routine "E"returns to the routine "monitor".

[0017] Upon branching into the routine "SP", a check is initiallycarried out at the start as to whether speed rules must be adhered to.When this is not required, a switch can be immediately made to thenext-lower rpm. This procedure can ensue via the monitoring routineuntil the drive turns with single rotational speed (approximately 500rpm). When speed rules are required, the rotational speed is adapted tothe requirements (for example, MPEG, 4-fold or audio, 1-fold) and isset.

[0018] In summary, the following operation thus derives. When the switchS is briefly pressed, for example for a maximum of only 0.5 seconds,then the processor 6 - via the motor control 7 - triggers a switching toa lower speed range. This operation can be repeated until previouslyoccurring vibrations and/or excessively high noise emissions have eitherentirely disappeared or have at least been capable of being reduced to abearable minimum extent. When the switch is pressed for a longer time,then the processor 6 triggers the ejection of the CD disk via the drawercontrol 8, whereupon the drawer together with CD disk is opened.

[0019] Given disturbing vibrations and/or noise emissions, the desiredspeed reduction can also be automatically produced with the assistanceof acoustic and/or vibration sensors whose signals are supplied to themotor control 7 via the processor 6.

[0020] The invention is not limited to the particular details of theapparatus depicted and other modifications and applications arecontemplated. Certain other changes may be made in the above describedapparatus without departing from the true spirit and scope of theinvention herein involved. It is intended, therefore, that the subjectmatter in the above depiction shall be interpreted as illustrative andnot in a limiting sense.

Claims
 1. A CD-ROM drive having a plurality of speed ranges selectablein n-fold graduation and having nearly reduced rotational speeds withineach speed range respectively between outer and inner sector, with theprescription that a reduction of the rpm automatically ensues given anegative read result, wherein a controller is provided that effect aswitching into a lower speed range given at least one of: a) an uppertransgression of a predetermined noise level, and b) when vibrationsoccur.
 2. The CD-ROM drive according to claim 1 , wherein at least oneof acoustic and vibration sensors are provided at the housing of thedrive, the output signals thereof influencing controllers in such a waythat a control signal for the purpose of reducing the speed is sent tothe motor control of the drive when a predetermined threshold isupwardly transgressed.
 3. The CD-ROM drive according to claim 1 ,wherein a manually actuatable key is allocated to the control means forspeed reduction.
 4. The CD-ROM drive according to claim 3 , wherein thekey-controlled speed reduction ensues with the assistance of theoperating key for the CD drawer transport.
 5. The CD-ROM drive accordingto claim 4 , wherein the control key for the drawer transport iscontrollable such that a speed reduction is triggered givenbrief-duration activation of the key and a transport movement of the CDdrawer is triggered given longer key pressure.
 6. A CD-ROM drive havinga plurality of speed ranges, comprising: a controller that assists aswitching to a lower speed automatically when read errors occur; and amanually actuatable key for switching the drive into a speed rangerespectively lower that is allocated to the controller for speedreduction.
 7. The CD-ROM drive according to claim 6 , furthercomprising: a CD drawer transport having a control key, wherein the keyfor switching into a lower speed range is combined with the control keyfor the CD drawer transport and respectively one of these two functionscan be triggered dependent on the duration of the key pressure.
 8. TheCD-ROM drive according to claim 7 , wherein the control key for thedrawer transport is controllable such that, given a brief activation ofthe key, a speed reduction is triggered and, given a longer keypressure, a transport motion of the CD drawer is triggered.
 9. TheCD-ROM drive according to claim 6 , wherein repeatedly pressing themanually actuatable key respectively switches the CD-ROM drive into alower speed range by one step for each press.